Metal gasket material plate and method for manufacturing the same

Abstract

(Problems to be Solved)The present invention is intended to provide a metal gasket material plate with which exfoliation of the coating or blister can be prevented even if it is used in the presence of an electrolyte aqueous solution and which can be manufactured through a process without use of hexavalent chromium in consideration of the environment, etc.(Means for Solving the Problems)The present, invention relates to a metal gasket material plate comprising a metal plate 1 having a rubber layer 4 on one side or both sides thereof through an adhesive layer 3, wherein a rust-resistant pigment is added to both of said adhesive layer 3 and said rubber layer 4.

Description

FIELD OF THE INVENTION[0001]The present invention relates to a metal gasket material plate and a method for manufacturing the same, the metal gasket material plate comprising a metal plate and a rubber layer, which is provided thereon through an adhesive layer. More particularly, the present invention relates to a metal gasket material plate that is suitable for a metal gasket, which is placed inside or around an engine, and relates to a method for manufacturing the same.BACKGROUND OF THE INVENTION[0002]Recently, laminated-type metal gasket material plates comprising a metal plate and a rubber layer, which is provided thereon through an adhesive layer are widely used as a material for metal gaskets, which is placed around an engine. Sealing of combustion gas, lubricant oil and cooling water in the engine is realized by using a gasket that is made by such metal gasket material plates.[0003]However, with such metal gasket material plates, there exists a problem of exfoliation of the r...

AI Technical Summary

Benefits of technology

[0008]The present invention is made for the purpose of advantageously solving the above problem. The metal gasket material plate according to the present invention is a laminated-type metal gasket material plate comprising a metal plate having a rubber layer on one side or both sides thereof through an adhesive layer, wherein a rust-resistant pigment is added to both of said adhesive layer and said rubber layer. According to need, a top coat material layer may also be provided over said rubber layer for the purpose of preventing blocking and improving slippage performance.

[0009]Further, a method of manufacturing a metal gasket material plate according to the present invention comprises steps of coating an adhesive agent containing a rust-resistant pigment in layer on one side or both sides of a metal plate that has been dried out after being subjected an alkaline degreasing treatment, forming an adhesive layer by drying and heating the adhesive agent, coating a rubber material containing a rust-resistant pigment in layer over said adhesive layer, and forming a rubber layer by drying and heating the rubber material. In addition, according to need, the method may also include the steps of coating a top coat material layer over said rubber layer and forming the top coat material layer by drying and heating the top coat material for preventing blocking and improving slippage performance.

[0010]According to the present invention of the metal gasket material plate and the method of manufacturing the same, exfoliation of the coating or blister can be prevented even if the metal gasket material plate is used in the presence of an electrolyte aqueous solution, because of the rust-resistant pigment prevents permeation of corrosive factors and a chemical film having high adhesiveness, which is formed as a result of a chemical reaction between the material of the metal plate and a negative ion that gradually dissolved out from the rust-resistant pigment by permeated water, prevents volume expansion (or shrinkage) of the adhesive layer and the rubber layer caused by permeation of the electrolyte aqueous solution. Further, because a surface preparation agent containing hexavalent chromium is not used, the metal gasket material plate can be manufactured through a treatment process without using hexavalent chromium, which is solicitous for the environment and the human body.

[0011]The metal gasket material plate of the present invention may also comprise a surface preparation agent layer containing trivalent chromium (chromium (III)), which is provided between said metal plate and said adhesive layer. The surface preparation agent is applied in the present invention for improving corrosion resistance performance of the surface of the material plate and improving adhesiveness between the metal plate and the adhesive layer formed over the metal plate. For this purpose, it is preferable to form a coating having a dry coating weight of 0.1 g / m2 or more and 2 g / m2 or less for one side, by coating a surface preparation agent containing trivalent chromium onto a surface of the metal plate and drying it. More specifically, it is preferable to form a coating , which formed by the surface preparation agent, having a dry coating weight of 0.3 g / m2 or more and 1.5 g / m2 or less for one side of the metal plate.

Problems solved by technology

However, with such metal gasket material plates, there exists a problem of exfoliation of the rubber layer.

Such exfoliation is likely to occur if water, LLC or electrolyte aqueous solution such as salt water, which is supposed to be sealed in the gasket, permeates the surface of the metal plate and exfoliates the coating and to cause a blister between the metal plate and the adhesive layer or between the adhesive layer and the rubber layer.

On the contrary, as for metal plates provided by surface preparation without using hexavalent chromium (meaning that the above advantages (1) to (3) are not realized) but with a coating of a normal rubber layer onto the surface through the intermediary of a normal adhesive layer, permeating of water, LLC or electrolyte aqueous solution such as salt water can occur, and as a result there still remains the problem that exfoliation of the rubber layer is likely to occur by exfoliation of the coating or the blister between the metal plate and the adhesive layer or between the adhesive layer and the rubber layer.

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